Sneaky Gugi banking trojan sidesteps Android OS security barricades

Overlay malware gets angry if you try and say no


Updated Gugi, a bank-account-raiding trojan for smartphones, has been retooled to bypass Android 6's security features designed to block phishing attempts and ransomware infections.

The modified malware forces users into giving it the ability to overlay genuine apps, send and view SMSes, make calls, and more. The software nasty is distributed through social engineering, usually with a spam SMS that encourages users to click on a malicious link.

The Gugi trojan is geared toward stealing users' mobile banking credentials by overlaying their genuine banking applications with counterfeit apps. The malware also attempts to seize credit card details using much the same trick of overlaying the Google Play Store app with hacker-controlled code.

Android OS version 6 was launched late last year with security features designed specifically to block such attacks. Among other things, apps now need the user's permission to overlay other apps, and to request approval for actions such as sending SMS messages and making calls.

Modifications of the Gugi trojan allow the malicious code to circumvent these two security controls.

Once installed on the device, the trojan sets about getting the access rights it requires. When ready, the malware displays the following sign on the user's screen: "Additional rights needed to work with graphics and windows." There is only one button: "Provide."

Users are subsequently presented with a screen asking them to authorize app overlay. After receiving this permission, the trojan blocks the device screen with a message asking for "Trojan Device Administrator" rights, before asking for permission to send and view SMS messages and to make calls. If the trojan does not receive all the permissions it needs, it completely blocks the infected device.

More on how the Gugi Android trojan bypasses elements of Android 6 security can be found on the Securelist.com blog here.

The Gugi banking trojan has been known about since December 2015, with the modified mobile malware first hitting the radar screens of security researchers in June 2016.

The vast majority (93 per cent) of users attacked by the Gugi trojan are based in Russia. Between April and early August 2016 there was a ten-fold increase in its number of victims, according to security researchers at Kaspersky Lab. ® Updated at 11.00 GMT September 9 to add: In a statement, Google said it was on top of the problem.

"We appreciate Kaspersky's research and their efforts to keep Android users safe. We're aware of this issue and the apps in question are currently being removed automatically on all devices with Verify Apps enabled. The applications were never published in Google Play."®


Other stories you might like

  • EnemyBot malware adds enterprise flaws to exploit arsenal
    Fast-evolving botnet targets critical VMware, F5 BIG-IP bugs, we're told

    The botnet malware EnemyBot has added exploits to its arsenal, allowing it to infect and spread from enterprise-grade gear.

    What's worse, EnemyBot's core source code, minus its exploits, can be found on GitHub, so any miscreant can use the malware to start crafting their own outbreaks of this software nasty.

    The group behind EnemyBot is Keksec, a collection of experienced developers, also known as Nero and Freakout, that have been around since 2016 and have launched a number of Linux- and Windows-based bots capable of launching distributed denial-of-service (DDoS) attacks and possibly mining cryptocurrency. Securonix first wrote about EnemyBot in March.

    Continue reading
  • Emotet malware gang re-emerges with Chrome-based credit card heistware
    Crimeware groups are re-inventing themselves

    The criminals behind the Emotet botnet – which rose to fame as a banking trojan before evolving into spamming and malware delivery – are now using it to target credit card information stored in the Chrome web browser.

    Once the data – including the user's name, the card's numbers and expiration information – is exfiltrated, the malware will send it to command-and-control (C2) servers that are different than the one that the card stealer module uses, according to researchers with cybersecurity vendor Proofpoint's Threat Insight team.

    The new card information module is the latest illustration of Emotet's Lazarus-like return. It's been more than a year since Europol and law enforcement from countries including the United States, the UK and Ukraine tore down the Emotet actors' infrastructure in January 2021 and – they hoped – put the malware threat to rest.

    Continue reading
  • Super-spreader FluBot squashed by Europol
    Your package is delayed. Click this innocent-looking link to reschedule

    FluBot, the super-spreader Android malware that infected tens of thousands of phones globally, has been reportedly squashed by an international law enforcement operation.

    In May, Dutch police disrupted the mobile malware's infrastructure, disconnecting thousands of victims' devices from the FluBot network and preventing more than 6.5 million spam text messages propagating the bot from reaching potential victims, according to Finland's National Bureau of Investigation on Wednesday.

    The takedown followed a Europol-led investigation that involved law enforcement agencies from Australia, Belgium, Finland, Hungary, Ireland, Spain, Sweden, Switzerland, the Netherlands and the US. 

    Continue reading
  • Watch out for phishing emails that inject spyware trio
    You wait for one infection and then three come along at once

    An emailed report seemingly about a payment will, when opened in Excel on a Windows system, attempt to inject three pieces of file-less malware that steal sensitive information.

    Researchers with Fortinet's FortiGuard Labs threat intelligence unit have been tracking this mailspam campaign since May, outlining how three remote access trojans (RATs) are fired into the system once the attached file is opened in Excel. From there, the malicious code will not only steal information, but can also remotely control aspects of the PC.

    The first of the three pieces of malware is AveMariaRAT (also known as Warzone RAT), followed by Pandora hVCN RAT and BitRAT.

    Continue reading
  • Now Windows Follina zero-day exploited to infect PCs with Qbot
    Data-stealing malware also paired with Black Basta ransomware gang

    Miscreants are reportedly exploiting the recently disclosed critical Windows Follina zero-day flaw to infect PCs with Qbot, thus aggressively expanding their reach.

    The bot's operators are also working with the Black Basta gang to spread ransomware in yet another partnership in the underground world of cyber-crime, it is claimed.

    This combination of Follina exploitation and its use to extort organizations makes the malware an even larger threat for enterprises. Qbot started off as a software nasty that raided people's online bank accounts, and evolved to snoop on user keystrokes and steal sensitive information from machines. It can also deliver other malware payloads, such as backdoors and ransomware, onto infected Windows systems, and forms a remote-controllable botnet.

    Continue reading
  • Symantec: More malware operators moving in to exploit Follina
    Meanwhile Microsoft still hasn't patched the fatal flaw

    While enterprises are still waiting for Microsoft to issue a fix for the critical "Follina" vulnerability in Windows, yet more malware operators are moving in to exploit it.

    Microsoft late last month acknowledged the remote code execution (RCE) vulnerability – tracked as CVE-2022-30190 – but has yet to deliver a patch for it. The company has outlined workarounds that can be used until a fix becomes available.

    In the meantime, reports of active exploits of the flaw continue to surface. Analysts with Proofpoint's Threat Insight team earlier this month tweeted about a phishing campaign, possibly aligned with a nation-state targeting US and European Union agencies, which uses Follina. The Proofpoint researchers said the malicious spam messages were sent to fewer than 10 Proofpoint product users.

    Continue reading
  • To cut off all nearby phones with these Chinese chips, this is the bug to exploit
    Android patches incoming for NAS-ty memory overwrite flaw

    A critical flaw in the LTE firmware of the fourth-largest smartphone chip biz in the world could be exploited over the air to block people's communications and deny services.

    The vulnerability in the baseband – or radio modem – of UNISOC's chipset was found by folks at Check Point Research who were looking for ways the silicon could be used to remotely attack devices. It turns out the flaw doesn't just apply to lower-end smartphones but some smart TVs, too.

    Check Point found attackers could transmit a specially designed radio packet to a nearby device to crash the firmware, ending that equipment's cellular connectivity, at least, presumably until it's rebooted. This would be achieved by broadcasting non-access stratum (NAS) messages over the air that when picked up and processed by UNISOC's firmware would end in a heap memory overwrite.

    Continue reading

Biting the hand that feeds IT © 1998–2022